Methods and apparatuses for processing or defining luminance/color regimes

An apparatus for processing (i) an input image signal (O) that comprises video images, the video images having been graded or defined in accordance with a maximum luminance value, the maximum luminance value being a coding peak brightness (PB_C) of an image encoding, wherein the coding peak brightness corresponds with an uppermost luminance of a luminance dynamic range (DR), the video images further having been encoded in a video transmission encoding suitable for communicating video to a video rendering-side, the video images for being processed to be rendered on one of various rendering-side video displays, the various rendering-side video displays having different output luminance dynamic ranges, wherein a respective output luminance dynamic range is defined by an uppermost luminance output that corresponds with a display-dependent display peak brightness (PB_D) of a respective rendering-side video display of the various rendering-side video displays, and (ii) an output description data signal (DDO) that comprises descriptive data (D) related to the video images, said apparatus comprising:

• an extractor adapted to extract the descriptive data (D) from an encoding of the output description data signal (DDO), wherein the descriptive data (D) specifies at least one luminance regime and comprises, for each respective at least one luminance regime, at least identification information for at least one subset of pixels of an input video image of the video images, wherein the identification information includes at least one luminance value (L_x) demarcating pixels having luminance respectively above or below the at least one luminance value (L_x);
• and
• a processing unit adapted to color process the input image signal (O), for a particular rendering-side video display having a respective display-dependent display peak brightness (PB_D) of the various rendering-side video displays having different output luminance dynamic ranges, to obtain an output image (IR′) to be rendered, based upon a color transformation processing determined from at least (i) the respective display-dependent display peak brightness (PB_D) of the particular rendering-side video display, and (ii) a formulation of luminance rendering as a function of at least the identification information.

A method of processing an input signal including descriptive data (D) of a description data signal (DDO) representative of an original image having been graded or defined in accordance with a maximum luminance value, the maximum luminance value being a coding peak brightness (PB_C) of an image encoding, wherein the coding peak brightness corresponds with an uppermost luminance of a luminance dynamic range (DR), the original image to be rendered on one of various rendering-side video displays, the various rendering-side video displays having different output luminance dynamic ranges, wherein a respective output luminance dynamic range is defined by an uppermost luminance output that corresponds with a display-dependent display peak brightness (PB_D) of a respective rendering-side video display of the various rendering-side video displays, the method comprising:

• extracting the descriptive data (D) from the input signal, wherein said descriptive data (D) specifies at least one luminance regime and comprises, for each respective at least one luminance regime, at least identification information demarcating at least one subset of pixels of the original image included in the at least one luminance regime;
• and
• processing the extracted descriptive data (D), for a particular rendering-side video display having a respective display-dependent display peak brightness (PB_D) of the various rendering-side video displays having different output luminance dynamic ranges, to effect color rendering of an image representative of the original image in response to (i) the respective display-dependent display peak brightness (PB_D) of the particular rendering-side video display of the various rendering-side video displays having different output luminance dynamic ranges and (ii) a formulation of luminance rendering of the at least one luminance regime as a function of at least the identification information.

An apparatus for processing an input signal including descriptive data (D) of a description data signal (DDO) representative of an original image having been graded or defined in accordance with a maximum luminance value, the maximum luminance value being a coding peak brightness (PB_C) of an image encoding, wherein the coding peak brightness corresponds with an uppermost luminance of a luminance dynamic range (DR), the original image to be rendered on one of various rendering-side video displays, the various rendering-side video displays having different output luminance dynamic ranges, wherein a respective output luminance dynamic range is defined by an uppermost luminance output that corresponds with a display-dependent display peak brightness (PB_D) of a respective rendering-side video display of the various rendering-side video displays, the apparatus comprising:

• an extractor for extracting the descriptive data (D) from the input signal, wherein said descriptive data (D) specifies at least one luminance regime and comprises, for each respective at least one luminance regime, at least identification information demarcating at least one subset of pixels of the original image included in the at least one luminance regime;
• and
• a processing unit adapted to process the extracted descriptive data (D), for a particular rendering-side video display having a respective display-dependent display peak brightness (PB_D) of the various rendering-side video displays having different output luminance dynamic ranges, to effect color rendering of an image representative of the original image in response to (i) the respective display-dependent display peak brightness (PB_D) of the particular rendering-side video display of the various rendering-side video displays having different output luminance dynamic ranges and (ii) a formulation of luminance rendering of the at least one luminance regime as a function of at least the identification information.

A method of adding display rendering specification information to an input image (I) of a set of video images, the video images having been graded or defined in accordance with a maximum luminance value, the maximum luminance value being a coding peak brightness (PB_C) of an image encoding, wherein the coding peak brightness corresponds with an uppermost luminance of a luminance dynamic range (DR), the display rendering specification information being usable by a receiving-side luminance processing apparatus to control a rendering of luminances of subsets of image pixels corresponding to at least one luminance regime subset of pixels with particular luminance values of one or more respective image(s) for various receiving-side video displays, the various receiving-side video displays having different output luminance dynamic ranges, wherein a respective output luminance dynamic range is defined by an uppermost luminance output that corresponds with a display-dependent display peak brightness (PB_D) of a respective receiving-side video display of the various receiving-side video displays, the method comprising:

• determining, via at least one of (i) an image processor, (ii) a display device, and (iii) a user interface, descriptive data (D) for use in specifying at least one luminance regime subset of pixels within the input image, wherein the descriptive data (D) comprises at least identification information for each respective at least one luminance regime subset of pixels of the input image, wherein the identification information includes at least one luminance value (L_x) demarcating pixels having luminance respectively above or below the at least one luminance value (L_x), wherein a receiving-side luminance processing apparatus for a particular receiving-side video display of the various receiving-side video displays having different output luminance dynamic ranges can determine a luminance rendering based upon (i) the respective display-dependent display peak brightness (PB_D) for the particular receiving-side video display and (ii) a formulation of luminance rendering of the at least one luminance regime as a function of at least the identification information;
• and
• encoding (i) the descriptive data (D) into an output description data signal (DDO) as metadata in a video transmission encoding signal (S′) suitable for communicating video to the receiving-side luminance processing apparatus, and (ii) an image (O) of pixels, derived from the input image, according to a video transmission encoding definition for the video transmission encoding signal (S′).

An image analysis apparatus for adding display rendering specification information to an input image (I) of a set of video images, the video images having been graded or defined in accordance with a maximum luminance value, the maximum luminance value being a coding peak brightness (PB_C) of an image encoding, wherein the coding peak brightness corresponds with an uppermost luminance of a luminance dynamic range (DR), the display rendering specification information being usable by a receiving-side luminance processing apparatus to control a rendering of luminances of subsets of image pixels corresponding to at least one luminance regime subset of pixels with particular luminance values of one or more respective image(s) for various receiving-side video displays, the various receiving-side video displays having different output luminance dynamic ranges, wherein a respective output luminance dynamic range is defined by an uppermost luminance output that corresponds with a display-dependent display peak brightness (PB_D) of a respective receiving-side video display of the various receiving-side video displays, the apparatus comprising:

• an image processor configured to determine descriptive data (D) for use in specifying at least one luminance regime subset of pixels within the input image, wherein the descriptive data (D) comprises at least identification information for each respective at least one luminance regime subset of pixels of the input image, wherein the identification information includes at least one luminance value (L_x) demarcating pixels having luminance respectively above or below the at least one luminance value (L_x), wherein a receiving-side luminance processing apparatus for a particular receiving-side video display of the various receiving-side video displays having different output luminance dynamic ranges can determine a luminance rendering based upon (i) the respective display-dependent display peak brightness (PB_D) for the particular receiving-side video display and (ii) a formulation of luminance rendering of the at least one luminance regime as a function of at least the identification information;
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• an encoder configured to encode (i) the descriptive data (D) into an output description data signal (DDO) in a video transmission encoding signal (S′) suitable for communicating video to the receiving-side luminance processing apparatus, and (ii) an image (O) of pixels, derived from the input image, according to a video transmission encoding definition for the video transmission encoding signal (S′).